Oh, well this was already discussed back an forth some ten
days ago - as most of this thread.

jcowan@reutershealth.com wrote:
> If they're lucky. The less lucky will only get default-UCA sorting. The
> least lucky will get nothing but binary codepoint sorting and a few
> language-specific hacks.

Non default-UCA collations are universally deployed.

Applications and tools with user- or community configurable
tailoring of collations are available, also as FOSS.

So, those stuck with 'default-UCA' are not less lucky, but less
willing to switch. This sounds like self-inflicted harm to me.